Idk if this makes sense.
Obviously not via sexual reproduction but could a person’s genetic parents be of the same sex and that person be genetically indistinguishable from the rest of the population?
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Interesting question, I found this
You can’t make a baby with two moms by simply fusing two eggs or adding one egg’s DNA to another’s. Even though the resulting embryo would have the usual 46 chromosomes, this wouldn’t work.
The reason isn’t some special string of A’s, G’s, T’s or C’s found in dad’s DNA. No, instead it has to do with chemical marks found on egg and sperm DNA. This methylation (as the marks are called) makes the DNA from each parent unique, and you need both to make a baby.
What these marks do is affect how at least 80 different genes are used. In science speak, these genes are imprinted.
As you may remember, we have two copies of each of our genes, one from each biological parent. The chemical marks shut off either the copy from the egg or sperm, depending on which has the marks present…
If an embryo’s DNA came from two parents of the same sex, then both copies of some of these imprinted genes will be shut off. And for the rest of these genes, both copies will be turned on. Embryos simply can’t survive when so many genes are out of whack. In fact, diseases like Angelman syndrome, Prader-Willi syndrome, and Beckwith-Wiedemann syndrome can happen when just one of these genes isn’t passed on properly.
You can read more here if you’re curious
I feel cheated by this answer because it seems like the limiting factor is in the natural process of embryo development and not in if the genetic material itself is compatible.
Further in the article it even says it could be possible from 2 sperm cells if you used stem cells to turn a sperm cell into an egg cell? So it is possible then. But only for males? Could you use stem cells to turn an egg cell into a sperm cell and accomplish a similar result from 2 egg cells?
…I’m left with a strong inconclusive as to whether it’s possible :(
To vastly oversimplify how genetics and embryonic development works, the “default” for humans is female and men have genetic codes that overwrites these defaults during fetal development. To put it more bluntly, males have extra code which females lack.
That could explain why sperm+sperm could theoretically work using a stem cell as a mediator to remove the excess code, while egg+egg can’t do the same because you’d need to manually scribe the extra genes directly.
…I’m left with a strong inconclusive as to whether it’s possible :(
Possible, yes. Possible with current technology and understanding, no.
The methylation of DNA and other ways that its functionality is modified is something that is studied in epigenetics. Such modifications can also be carriers of heritable traits (ex. a study on Icelandic families found that experiencing famine could change the likelihood of diabetes two generations later). Modifying methylation has also been investigated for treatment of genetic diseases.
Conceivably, epigenome editing could be used to modify the sperm/egg methylation to make them compatible. But, that’s probably a ways a way from being practical.
It’s likely possible, but not at this stage of humanity. The human genome was only unlocked in the past few decades.
Gotta remember, the body of science of any field is still itself growing. More information becomes clear all the time. What was once considered impossible is now everyday boring stuff.
There are limitations to what we can do, and what we know we can do. It isn’t until we test more and try different things and unlock new technologies that the impossible becomes possible.
It seems like it should be possible but there is a lot that stem cells seem to make possible that realistically we don’t know how to make them do. Only time will tell what we learn how to do.
The answer does say
The reason isn’t some special string of A’s, G’s, T’s or C’s found in dad’s DNA.
It’s true that two same-sex parents of either sex have the basic genetic information to create a female child (a male child needs at least one male parent) but the natural process of embryo development is a big deal!
You seem to fixated on the aspect of feasability.
Don’t you think there may be good reasons for these limiting factors (even when we have not discovered them)?
It makes me think that we still don’t know enough about the true meaning of these dna parts.
Great post - I figured that this would be the case based off of the idea that, whether you are male or female, certain markers can only be passed on through father/mother…
Your haplogroup, for instance, always comes from the father. It would seem to me, then, that things like haplogroups would only be linked to male genetics, and simply smushing together two men’s genetics would result in things like repeat haplogroups and a total lack of mtDNA.
Perhaps, eventually, technology would exist that could translate the haplogroup of a female into the genetic code necessary for reproductive genetic combination, and likewise extract female-specific reproductive code from a male and do the same… But yeah, I imagine that would also just be the point of full genetic customization from top to bottom, and so the ability to do that would no longer be surprising but simply something that has come to us as a byproduct of advanced gene editing.
This is wildly interesting. I know I’m far from smart, but I would have thought I would have known this by now.
Thank you for the summarized information.
There are three genomes that go into an embryo. One from the chromosomes of the large gamete, the egg, one from the chromosomes of the small gamete, the sperm, and one from the mitochondria, in humans from the egg as well. If you had two XX donors you could make XX kids. If you had two XY donors you could make XX, XY, and YY variants. The only viable ones would be XY and XX, YY would not reach gestation.
That said, if you took the DNA from gametes from each, removed the nucleus and mitochondria of an egg, added the total gametic DNA from both to the cell, added a mitochondria from either donor, then it should, in theory, be a viable egg like in IVF. This is actually a strategy for dealing with a mitochondrial disease by donating mitochondrial DNA from another source rather than those impacted by the disease. The problem would be there are many ways for this to go wrong and be left with an unviable embryo, so it would likely take many many eggs and many many donated cells to get a single viable egg with the donated DNA. That said, it could technically work.
There are a number of less optimal combinations, as well, such as XXY, XYY, and XXYY.
There’s an in development technology called in vitro gametogenesis (IVG) that would allow same sex couples as well as infertile people to have biological children. It’s been in the works for over a decade and as far as I am aware has not yet been tested on humans.
For two females, you would have to implant one egg’s DNA into a sperm whose DNA was “stripped out” And for two males, the same but transferred into an egg. I’d say it could be done in the near future with the progress we did with CRISPR in the last decade, for instance.
Hand waving away a lot of the developmental process, you could make a male or female offspring from 2 males or a female offspring from 2 females that would be indistinguishable from the variety in the normal population.
The obvious solution would be to just clone the parent.
Any hypothetical attempt to simulate recombination would produce a genetic clone at best—but more likely (even if you overcame the practical issues), you’d end up replacing some of the unique material on one half of each chromosome with a copy of the genes on the other half (with a corresponding increase in the risk of genetic defects).
Yeah cloning isn’t really what I’m asking about. Interested in knowing if you can make offspring from two same sex parent cells that have similar genetic makeup/diversity to offspring with 2 different sex parent cells
I know—I’m just saying that any other theoretical solution would always be worse than cloning, because you’d lose genetic information.
Edit: See Isodisomy for details.
Under ideal conditions, I don’t see how this would lose any more genetic information than sexual reproduction with parents of the opposite sex. The problems you’re referring to seem to be more of an issue if two gametes were supplied by a single parent.
This called parthenogenesis, and is a main plot line in the book Seveneves…
Not a biologist, but I’m convinced it’s possible.
With induced pluripotent stemcells (stemcells made from nearly any cell of the body which can grow into anything too), we’ll find a way to make an egg from a man using any cells he provides. Then all you need is the other male partner’s sperm and a donor womb. Btw, the womb won’t have to be within a woman - artificial wombs are being researched.
Someone already posted the 3 parent technique. So it is at least already partially possible.
Since males have the XY chromosomes, they should be able to (theoretically) have female (XX) and male (XY) offspring. With advanced microbiology and artificial wombs, there’s no doubt in my mind that we’ll reach that point before the end of the century.
Obligatory “I’m not a biologist” disclaimer
You could take an X chromosome from both parents either way. And I’m pretty sure all the other chromosomes wouldn’ make that much of a difference
I had the same thought. Like the extent of my knowledge is needing either XX or XY and getting half from each parent but not really sure on the rules or specifics for how things go
Not a biologist either. As a thought experiment it seems possible, with two women able to have a daughter, and two men either to have either a daughter or a son.
It sits one step beyond what we’ve already done to produce a child that has (in a sense) three genetic parents: https://www.ox.ac.uk/research/three-parent-baby-raises-issues-long-term-health-risks
Edit: another post already has shared that no, this isn’t possible. Thank you @NOT_RICK@lemmy.world .
